1. Field of the Invention
This invention relates to a radiation image read-out and displaying apparatus for obtaining an image signal by reading out a radiation image, and reproducing and displaying a visible radiation image by use of the image signal.
2. Description of the Prior Art
Techniques for reading out a recorded radiation image in order to obtain an image signal, carrying out appropriate image processing on the image signal, and then reproducing a visible image by use of the processed image signal have heretofore been known in various fields. For example, there has been proposed a system wherein an X-ray image is recorded on an X-ray film having a gamma value designed so as to match the type of image processing to be carried out, the X-ray image is read out from the X-ray film and converted into an electric signal, and the electric signal (image signal) is image-processed and then used for reproducing the X-ray image as a visible image on a copy photograph or the like. In this manner, a visible image having good image quality with high contrast, high sharpness, high graininess or the like can be reproduced.
Also, when certain kinds of phosphors are exposed to radiation such as X-rays, .alpha.-rays, .beta.-rays, .gamma.-rays, cathode rays or ultraviolet rays, they store part of the energy of the radiation. Then, when the phosphor which has been exposed to the radiation is exposed to stimulating rays such as visible light, light is emitted by the phosphor in proportion to the amount of energy stored during exposure to the radiation. A phosphor exhibiting such properties is referred to as a stimulable phosphor. As disclosed in U.S. Pat. Nos. 4,258,264, 4,276,473, 4,315,318 and 4,387,428 and Japanese Unexamined Patent Publication No. 56(1981)-11395, it has been proposed to use stimulable phosphors in radiation image recording and reproducing systems. Specifically, a sheet provided with a layer of the stimulable phosphor (hereinafter referred to as a stimulable phosphor sheet) is first exposed to radiation which has passed through an object such as the human body in order to store a radiation image of the object thereon, and is then scanned with stimulating rays, such as a laser beam, which cause it to emit light in proportion to the amount of energy stored during exposure to the radiation. The light emitted by the stimulable phosphor sheet upon stimulation thereof is photoelectrically detected and converted into an electric image signal, and by using the image signal the radiation image of the object is reproduced as a visible image on a recording material such as photographic film, a display device such as a cathode ray tube (CRT), or the like.
Radiation image recording and reproducing systems using stimulable phosphor sheets are advantageous over conventional radiography using silver halide photographic materials in that images can be recorded even when the energy intensity of the radiation to which the phosphor sheet is exposed varies over a wide range. More specifically, since the intensity of light emitted upon stimulation after the radiation energy is stored on the stimulable phosphor varies over a wide range and is proportional to the amount of energy stored during exposure to the radiation, it is possible to obtain an image having a desirable density regardless of the energy intensity of the radiation to which the stimulable phosphor sheet was exposed, by setting an appropriate read-out gain when reading out the emitted light and converting it into an electric signal to be used in reproducing a visible image on a recording medium or a display device.
Radiation image read-out and displaying apparatuses used in the aforesaid radiation image recording and reproducing systems are often required to process a large number of radiation images. By way of example, a radiation image read-out and displaying apparatus on such a large scale may be constituted of an image signal gathering section and an image processing and displaying section which are located remote from each other in separate rooms or the like. The image signal gathering section is constituted so as to obtain image signals by reading out radiation images, and enter ID information giving specifics about the image signals such as the name of the object recorded, the portion of an object, the image of which was recorded, or the date on which the image was recorded. The image processing and displaying section stores the image signals, carries out image processing of the image signals, and reproduces and displays visible radiation images by use of the processed image signals. The image signal gathering section and the image processing and displaying section are connected through cables or the like so that image signals and other signals sent from the image signal gathering section are received by the image processing and displaying section.
In the aforesaid radiation image read-out and displaying apparatuses, instructions about the type of image processing which is to be carried out on an image signal obtained in the image signal gathering section, the type of image display means on which a reproduced image is to be displayed when a plurality of image display means are provided, or the like are input at a console keyboard, which constitutes the image processing and displaying section, or the like.
In a large-scale radiation image read-out and displaying apparatus wherein a large number of radiation images should be processed, both the image signal gathering section and the image processing and displaying section are large, and necessary functions are shared therebetween. Therefore, the image signal gathering section and the image processing and displaying section are often provided at locations remote from each other, for example, in separate rooms as described above. In such cases, when the image signals obtained in the image signal gathering section must be processed immediately, for example, when it is urgent for the image signals to be processed and for visible images to be reproduced from the image signals after they are obtained, it is necessary for operators to be assigned to both the image signal gathering section and the image processing and displaying section. Alternatively, after the image signals are obtained in the image signal gathering section, an operator may move from the location of the image signal gathering section to the location of the image processing and displaying section in order to carry out the necessary operations. Therefore, the operating efficiency of the system as a whole becomes low.